Immunology. = complement, n. 5i. Now chiefly historical.

Biochemistry. A thermolabile protein complex found in blood plasma and other body fluids, which by combining with an antigen-antibody complex can…

a cytokine that stimulates the proliferation and differentiation of monocytes and macrophages; cf. M-CSF n. at M, n. initialisms 1.

= macrophage colony-stimulating factor n. at macrophage, n. compounds.